Jump Start With Python - Part 5 (Numbers)

Introduction

• Jump Start With Python - Part 1
• Jump Start With Python - Part 2
• Jump Start With Python - Part 3
• Jump Start With Python - Part 4 (Strings)

• int (Integers): Positive or negative whole numbers with no decimal point.
• long: They are also known as long integers of unlimited size. They are usually followed by a postfix (l/L).
• float: Floating point numbers represent real numbers and are written with a decimal point dividing integer and fractional parts.
• complex: Complex numbers are of the form (x + yJ), where x and y are floating point real values and J represents the square root of -1 i.e. an imaginary number.

• Type Method: It consists of one parameter:
  1. var_name: It is the variable to be checked.
  Syntax: type(var_name)
  
• Isinstance Method: It consists of two parameters:
  1. var_name: It is a variable to be checked.
  2. type: It is a number datatype to be checked with respect to a variable. It is a class name of the numeric data type.
  Syntax: isinstance(var_name, type)
  

There are some limitations in the float data type, which are actually limitations of computer hardware. It can be explained using the example below:

To overcome this problem, we have the decimal module in Python which have precision as per user-specific scenario compared to floating-point numbers which have precision up to 15 decimal points. The Python decimal module is explained below:

Creating fractions using Fractions Module

There are many ways to create fractions using Fractions module. They are explained below:

• Bit Length Method
  This method returns the number of bits required to represent an integer in binary. This method excludes sign convention and leading zeros also, it requires an integer to be converted to binary first.
  Syntax: var_name.bit_length()
  
• To Bytes Method
  This method returns an array of bytes representing the integer specified as input. It consists of three parameters that are explained below:
  1. length: To specify byte length for respective integer. Overflow Error is raised if the length is not according to integer specified.
  2. byteorder: To specify the byte order there are two schemes for byte order, "big" and "little". If "big" is specified, then the most significant byte is
  at the start of an array while in the case of "little" it is at the end of the array.
  3. signed: It determines whether two's complement is used to represent the integer or not. If it is "False" a negative integer is given and vice-
  versa. By default its "False".
  Syntax: int_num.to_bytes(length, byteorder, *, signed)
  
• From Bytes Method
  It is a class-level method. This method returns the integer represented by array of bytes specified as input. It is the inverse of the To Bytes Method. It consists of three parameters that are explained below:
  1. bytes: A byte object that is to be converted into an integer.
  2. byteorder: To specify the byte order, there are two schemes, "big" and "little". If "big" is specified then most significant byte is at starting of array while in case of "little" it is at the end of array.
  3. signed: It determines whether two's complement is used to represent the integer or not. If it is "False" a negative integer is given and vice-versa. By default its "False".
  Syntax: int.from_bytes(bytes, byteorder, *, signed)
  

• Integer Ratio Method: This method returns the pair of integers whose ratio is exactly equal to the original floating-point number along with a positive denominator.
  Syntax: float_num.as_integer_ratio()
  NOTE: It raises Overflow Error in the case of infinities and Value Error in the case of NaNs (Not-a-Number).
  
• Is Integer Method: This method returns True if float instance is a finite integer and False otherwise.
  Syntax: float_num.is_integer()
  
• Hex Method: It is an instance method. This method returns a hexadecimal string for a floating-point number specified as input. For finite numbers, the hexadecimal string is led by the prefix "0x" and postfixed by "p" and exponent.
  Syntax: float_num.hex()
  
• From Hex Method: It is a class method. It returns the floating-point number represented by the hexadecimal string specified as input. It consists of one parameter and it is explained below:
  1. hex_num: It is a hexadecimal string that will be converted to a floating-point number.
  Syntax: float.fromhex(hex_num)